77 lines
2.5 KiB
ReStructuredText
77 lines
2.5 KiB
ReStructuredText
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.. SPDX-License-Identifier: CC-BY-SA-2.0-UK
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**********************
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Kernel Development FAQ
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**********************
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Common Questions and Solutions
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==============================
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Here are some solutions for common questions.
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How do I use my own Linux kernel ``.config`` file?
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--------------------------------------------------
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Refer to the
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":ref:`kernel-dev/common:changing the configuration`"
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section for information.
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How do I create configuration fragments?
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----------------------------------------
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A: Refer to the
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":ref:`kernel-dev/common:creating configuration fragments`"
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section for information.
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How do I use my own Linux kernel sources?
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-----------------------------------------
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Refer to the
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":ref:`kernel-dev/common:working with your own sources`"
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section for information.
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How do I install/not-install the kernel image on the root filesystem?
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---------------------------------------------------------------------
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The kernel image (e.g. ``vmlinuz``) is provided by the
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``kernel-image`` package. Image recipes depend on ``kernel-base``. To
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specify whether or not the kernel image is installed in the generated
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root filesystem, override ``RRECOMMENDS:${KERNEL_PACKAGE_NAME}-base`` to include or not
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include "kernel-image". See the
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":ref:`dev-manual/layers:appending other layers metadata with your layer`"
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section in the
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Yocto Project Development Tasks Manual for information on how to use an
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append file to override metadata.
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How do I install a specific kernel module?
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------------------------------------------
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Linux kernel modules are packaged individually. To ensure a
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specific kernel module is included in an image, include it in the
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appropriate machine :term:`RRECOMMENDS` variable.
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These other variables are useful for installing specific modules:
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- :term:`MACHINE_ESSENTIAL_EXTRA_RDEPENDS`
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- :term:`MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS`
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- :term:`MACHINE_EXTRA_RDEPENDS`
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- :term:`MACHINE_EXTRA_RRECOMMENDS`
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For example, set the following in the ``qemux86.conf`` file to include
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the ``ab123`` kernel modules with images built for the ``qemux86``
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machine::
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MACHINE_EXTRA_RRECOMMENDS += "kernel-module-ab123"
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For more information, see the
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":ref:`kernel-dev/common:incorporating out-of-tree modules`" section.
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How do I change the Linux kernel command line?
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----------------------------------------------
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The Linux kernel command line is
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typically specified in the machine config using the :term:`APPEND` variable.
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For example, you can add some helpful debug information doing the
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following::
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APPEND += "printk.time=y initcall_debug debug"
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